The State of Web Vitals

A/B testing impact

Performance impact by ab_testing provider.

Field data PhoneDesktopAll Scope All sites Q2 2026 edition · All devices field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for A/B testing impact

Performance impact by ab_testing provider.

8
Providers ranked
After min-sites filter
21,106
Sites in sample
Combined across all items
2.2s
Best LCP (p75)
Google Optimize
The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
2

The ranking sorted by LCP at p75, fastest first

# Provider LCP p75 Passing Sites
1 Google Optimize 2.2s 82.2%
19,928
2 AB Tasty 2.3s 77.9%
109
3 VWO 2.4s 77.7%
433
4 Kameleoon 2.4s 77.3%
112
5 Dynamic Yield 2.6s 69.8%
65
6 Convert 2.7s 69.8%
191
7 Optimizely 2.7s 69.4%
137
8 LaunchDarkly 3.9s 48.8%
131
The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
3

Passing LCP per provider which group passes the LCP most often

ProviderSitesPassing LCPp75
Monetate 0% 26 89% 2.3s
Google Optimize 10.5% 19,928 82% 2.2s
AB Tasty 0.1% 109 78% 2.3s
VWO 0.2% 433 78% 2.4s
Kameleoon 0.1% 112 77% 2.4s
Convert 0.1% 191 70% 2.7s
Dynamic Yield 0% 65 70% 2.6s
Optimizely 0.1% 137 69% 2.7s
LaunchDarkly 0.1% 131 49% 3.9s
Split.io 0% 9 33% 3.3s
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good LCP (2.5s at p75) · one value per site

82% of Google Optimize sites pass LCP. LaunchDarkly trails 33 points behind, leaving 51% of its sites failing. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
4

All five vitals at once the whole category without toggling - cell is the pass rate, small number the p75

LCP
INP
CLS
FCP
TTFB
Google Optimize 10.5%
822.2s
96104ms
860.05
751.8s
551.3s
VWO 0.2%
782.4s
80179ms
840.05
721.9s
551.2s
Convert 0.1%
702.7s
86182ms
800.08
751.9s
551.4s
Optimizely 0.1%
692.7s
73205ms
800.09
642.2s
461.3s
LaunchDarkly 0.1%
493.9s
76197ms
730.11
492.7s
551.2s
Kameleoon 0.1%
772.4s
71210ms
710.12
721.9s
531.1s
AB Tasty 0.1%
782.3s
86169ms
720.12
711.9s
61988ms
Dynamic Yield 0%
702.6s
47295ms
640.19
751.8s
61967ms
Monetate 0%
892.3s
71214ms
770.08
771.7s
391.0s
Split.io 0%
333.3s
63267ms
440.34
442.6s
56884ms
60%95%+ passing Cell: pass rate, small number = p75 · faded rows: under 100 sites

One row per provider, one column per vital - the cell is the share of sites passing, the small number the p75. No toggling needed to see where the category actually differs.

Google Optimize leads on LCP: 82% of its sites pass. LaunchDarkly trails at 49%. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · all devices field datacorewebvitals.io/state-of-cwv
Related signals Maps (4) → CDN (15) → Chat & messaging (17) → Bot detection (7) → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured